lengthOfLIS.swift

func lengthOfLIS(_ nums: [Int]) -> Int {
    if nums.isEmpty { return 0 }
    let len = nums.count
    var dp  = Array(repeating: 0, count: len)
    dp[0] = 1
    var ans = 1
    for i in 1..<dp.count {
        var maxVal = 0
        for j in 0..<i {
            if nums[i] > nums[j] {
                maxVal = max(maxVal, dp[j])
            }
        }
        dp[i] = maxVal + 1
        ans = max(ans, dp[i])
    }
    return ans
}